How to Protect Your Classic Car's Rubber Seals

02 August 2018

As much as we love our classic cars, there’s likely not a single owner among us who doesn’t feel a slight prang of resentment when something goes wrong, fails or wears out. And that happens. Quite a lot.

We’ll all be aware of the ravages of rust and corrosion, the sheer hair-tearing frustration of attempting to diagnose electrical gremlins and the disappointment of discovering faded, cracking paintwork. But although it might be lesser known, problems with your car’s rubber components can be just as serious a malady for your classic vehicle.

As rubber ages, it dries out and shrinks. Given the sheer number of rubber components used in any one vehicle, the aging of the material can cause calamites from leaks and whistles to soggy handling and even more serious issues with cooling, fueling and braking. Here’s some of the more common issues you might encounter with your car’s rubber bits and bobs, plus some top tips on taking care of them.

Weather Stripping And Seals

One of the more common problems older vehicles will encounter is when the weatherstripping that surrounds the doors, windows, headlights and taillights starts to corrode. As the rubber rots and shrinks, it will no longer be able to form an effective seal against the elements.

This can manifest itself in a variety of ways, but the most common will be an increase in whistling wind noise while you’re driving along and moisture making its way into your interior.

In particularly bad cases, leaky weatherstripping can cause water to leak into your boot or cabin every time in rains. This can wreak havoc on electrics, can encourage the development of rust and will also cause carpeting or leather upholstery to grow mould and rot.

How To Look After Your Car’s Weather Stripping

Particularly if you don’t have access to a garage or a storage unit, faulty weather stripping can quickly take its toll on your vehicle’s health. Worse still, replacement weatherstripping can be ridiculously expensive for older vehicles so it pays to try and keep yours maintained as well as possible.

Luckily, it’s fairly easy to keep weather stripping and seals in good nick simply by applying a little silicone grease every six months or so. You can buy grease specifically for use on weatherstripping, or alternatively tyre slick products used to restore and nourish your tyre rubber will work just as effectively.

Simply apply some of the grease to your weatherstripping and seals, leave to dwell for a few minutes and then wipe off any excess with a towel. Integrate it into your detailing routine every time you wash or clean out your vehicle and you can keep it looking and performing great for years to come.

Just be sure to never use Vaseline or any other petroleum-based product on your car’s rubber components, as this will cause the rubber to rot and corrode at a much faster rate.

Replace Rubber Bushings And Mounts

The rubber used for the bushings in your car’s suspension and steering systems, as well as for the mounts that hold your engine and transmission in place, will also wear and degrade over time.

This will cause your vehicle’s handling to deteriorate, leaving the car feeling stodgy to drive and decreasing your confidence in its abilities. Worn motor and transmission mounts will increase rattles, vibrations and noise while driving and in some case can even crack apart, leaving your engine and gearbox free to move about or even fall out!

If you’re unsure of what the next upgrade for your vintage car should be, we’d suggest investing in a good set of new bushings for your suspension and steering. Polyurethane bushes made by the likes of SuperPro are an easy and relatively inexpensive improvement, but can completely transform the way your car drives.

Given the stiffer consistency of polyurethane over rubber, these bushings can restore handling and steering feel to better than factory standard. Poly doesn’t corrode like rubber either, so it can be a one-and-you’re-done fix that’ll leave your car feeling great for years to come.

When it comes to replacing engine and transmission mounts however, we'd recommend sourcing rubber replacements instead of opting for polyurethane. In many cases, the stiff poly mounts will only serve to further increase vibration and noise. This can be a great addition to any track car, but for a weekend driver it may be too extreme a modification for some.

Check Your Rubber Hoses And Lines

Now we’re into the really vital stuff: rubber hoses are used all over your car, from the fuel lines which transfer fuel into your engine to oil hoses that lubricate your vehicle’s components to cooling pipes, intake hoses and brake lines.

The failure of any of these could prove catastrophic to your car, and most are subjected to constant stress and varying temperatures purely by means of their operation. Keeping a vigilant eye out for any cracks, leaks or splits in your vehicle’s various hoses and lines is incredibly important.

If you spot an issue, have it replaced with a new hose or pipe as soon as possible. Luckily these are relatively inexpensive and in most cases are easy to replace, whether you do it yourself at home or have a professional mechanic do it for you.

Compared to those of modern vehicles, the brakes on older cars can seem terrifyingly weedy by comparison. As a result, one of the better bang-per-buck upgrades we’d recommend would be replacing your classic car’s standard rubber brake hoses with stainless steel ones.

Due to the fact the steel mesh lines can hold pressure and resist flexing much better than rubber, stainless brake hoses can vastly improve braking response and performance, making your car safer to drive and affording you much more confidence in it. Plus they won’t corrode or wear out over time, making it a true one-and-done upgrade that’s cheap and easy to do.

Keep An Eye On Your Classic Car’s Tyres

Relatively unglamorous they may be, but make no mistake about it: tyres are the single most important part of your car, and so it’s absolutely vital that you ensure yours are kept in proper condition.

Of all the above, the one thing you really don’t want to wear out on you is your tyres. If your tread depth is past its minimum point, if you spot any any bulges in the sidewall or cracks in the rubber, you should replace your tyres as soon as possible – ideally with the best replacements you can afford.

For cars that spend much of their time laid up, you can extend the lifetime of rubber by using tyre gel or tyre slick products; these simply are applied on to your rubber and will give you the benefit of absorbing into and nourishing the rubber and also giving your car that smart factory-fresh look. You’d be surprised how much taking care of your tyres can improve the look of your car!

Not only that, but modern tyre technology has come on leaps and bounds in the past few decades, to the point where a good set of modern tyres can have a transformative effect on your classic car’s abilities.

Vehicles which might previously have had reputations for wayward handling characteristics can be effectively tamed and enjoyed much more when wearing a good set of modern rubber. Most big-name tyre manufacturers now offer ranges specifically to suit the smaller and narrower wheels that came as standard on many older cars, meaning you can’t use lack of availability as an excuse.

Think about it this way: regardless of how fast your car is or how strong your brakes are, the only thing keeping you and your vehicle from careening off into a hedge is four patches of rubber no bigger than the palm of your hand. That’s worth keeping in good shape, right?